1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method which correct the brightness of a photographed photograph-image.
2. Description of the Related Art
The brightness of the photograph-image photographed by a camera apparatus depends on the environment in which a subject is placed, and others, and is greatly affected by the change of photographing conditions such as the ever-changing location and amount of light of a light source, particularly if the photographing is executed in the outdoor environment where the light source is the sunlight.
Therefore, the various approaches for correcting the brightness have been devised to cause a photographed image to be good. For example, an approach for adjusting the brightness in an area of a subject and a background, respectively to correct the influence by a backlight has been devised.
A view-monitor system has been devised and implemented, which photographs a circumstance outside a vehicle, a blind spot of a driver, with a camera apparatus mounted in the vehicle and displays it on a monitor inside the vehicle. Since the purpose of such a view-monitor system is that a driver may understand a circumstance outside a vehicle, a blind spot of a driver, it is preferable to be able to visually recognize well a whole image photographed by a camera apparatus mounted as capable to photograph an area of a blind spot. That is, in such a view-monitor system mounted in a vehicle and others, since an area to keep an eye on is different according to a circumstance, it is preferable that the brightness of a photographed image be uniform as a whole regardless of the distinction such as a subject and a background.
Thus, while the influence by a backlight, for example, has been produced in an image photographed by such a view-monitor system, and the brightness is adjusted in an area of a subject and a background, respectively like the above backlight correction, the image required for the system can not be obtained.
Japanese Patent Laid-Open No. 2000-069354 discloses an approach which corrects the brightness of a photographed image to be uniform as a whole regardless of the distinction such as a subject and a background by adjusting an exposure time of a camera apparatus.